Weak AC output on passenger side vents
 

2004 E500

Hi guys!

AC output is strong on the drivers side, but weak on the passenger side vents. Both sides are cold. The air is cold and strong to the center rear vents as well. Any thoughts?

Thanks,
Tarey

Sounds like you have a issue with one of the flaps that direct both heated and cooled air into the cabin-------the problem is that unlike the W210's with self diagnostics, you don't have that on the W211-----what are you left with---more mumbo jumbo or define the problem----if you opt for defining the problem then you need someone with factory diagnostics or equal to edit the AC control module and cryogenic system

which vents exactly do you mean.. side passengers by the door? those can be weak due to auto mode. Mine barely blows when climate control set to auto.

There are loads of actuators and flaps in the system and for me it is hard to explain in text form------it's all spelled out pictorialy in the owners manual. Besides have you educated yourself an possibly googled the MB system to learn what you drive!!

you have DAS Xentry ?

You betsha and a couple of versions!!

It's weak in Auto and Manual modes coming out of the passenger center vent and the passenger dash pillar vent. I just purchased this car 4 days ago, moving out of my w210, so the point is well taken... I have been Googling and youtubing for possible solutions. My first thought was perhaps the blower voltage was messed with by a previous owner via the hidden ac functions or perhaps a duo valve is going bad... My w210 had a similar problem with the blower motor regulator which affected the volume of air for the whole blower. Wasn't sure if the w211 has a regulator for each side, where one is going bad. One note however is that it works well in heater mode, which might rule that out. I've rotated the vent controls in order to actuate the vent doors and they seem to be functioning, although I can be certain the doors are closing all the way. You expertise is greatly appreciated... It will be +115 F for 2 more months here in Phoenix...

Check your Freon

I had a 2003 E500. I think there is nothing wrong with your vents. The AC adjustment of vents is quirky and controlled by the two controls, one for driver and the other for passenger side. You need to adjust the passenger vent by pulling out the outer ring and rotate it according to the arrow pointing to the center vent, upper vent and foot vent, etc.